The pump is an important equipment for RMR of deep-sea drilling， usually placed in deep water. In order to conveniently monitor the operation and working parameters of the pump in the ship deck control room， this paper designs an RMR underwater pump monitoring system. The hardware of the system includes three parts： underwater measurement and control unit， umbilical cable， and deck monitoring unit， which are responsible for collecting pump working parameters and working screens， supplying power and transmitting information to the pump， displaying and controlling pump working parameters. The use of optical transceivers and umbilical cables can achieve long-distance signal transmission. The underwater measurement and control unit adopts two PLCs of the same specifications， which have the advantage of modular design. The upper computer of the system is programmed using LabVIEW software， which has the advantages of simple operation and user-friendly interface. The lower PLCs is programmed using Easybuilder software， which has the advantages of powerful library functions and good readability. The upper computer and lower computer communicate through the standard Modbus RTU protocol. The system underwent software and hardware integration testing， and the upper computer was able to read and display data from external devices of the lower computer normally， control the on/off， start/stop of external devices， indicating that the system can well meet the monitoring requirements of RMR underwater pump. And the system also has advantage such as scalability.